Electrochemical sensors typically have a baseline output signal that fluctuates over time, temperature, and voltage potential. This baseline signal is generally undesirable since it is often indistinguishable from a signal produced by a parameter being measured by the electrochemical sensor. Conventionally, such baseline signal is removed by employing a reference electrochemical sensor that produces the baseline signal, but does not produce the signal associated with the parameter being measured, in conjunction with a primary electrochemical sensor that produces a total signal comprising the baseline signal and the signal associated with the parameter being measured. The difference between the total signal produced by the primary electrochemical sensor and the signal produced by the reference electrochemical sensor is the signal associated with the measured parameter. Conventionally, electrochemical sensors produce output current signals that are converted to voltage or a digital format for analysis, such as subtracting a primary signal from a reference signal as discussed above. This generally requires the primary electrochemical sensor and the reference electrochemical sensor to each have a separate readout circuit to convert the output current signal. This is not an issue in an environment where power requirements and physical space are not limiting factors, such as a non-portable electrochemical sensing device. However, where power requirements and physical space are limited (e.g., such as with respect to a contact lens), employment of multiple readout circuits can be problematic.